def hop():
    """
    Calling hop returns a curried version of the function f(x, y) = y.
    >>> hop()(3)(2) # .Case 1
    2
    >>> hop()(3)(7) # .Case 2
    7
    >>> hop()(4)(7) # .Case 3
    7
    """

    def level1(x):
        def level2(y):
            return y
        return level2
    return level1

'''这是我做的，但官网答安就一行

return lambda x: lambda y: y
'''